Leucine May Boost Muscle Synthesis for Athletes
Many athletes drink high protein beverages to increase their muscle synthesis. However, a recent study found that adding leucine to low-protein beverages may result in almost the same amount of muscle synthesis as a protein beverage with five times the protein.
Participants in the study included 40 men with an average age of 21.
They were given one of five beverages:
1. a lower protein beverage containing 6.25 grams of whey protein and 0.75 grams of leucine;
2. the same beverage with three grams of leucine;
3. the same beverage with six grams of leucine;
4. the same beverage with a mix of 5.0 grams of leucine plus iso-leucine, and valine;
5. or a high protein beverage with 25 grams of whey protein that included 3 grams of leucine.
The researchers measured muscle synthesis while the men were resting and while they were exercising. They found that the high protein beverage resulted in the highest rate of muscle synthesis (267%), with the low protein plus 5 grams of leucine beverage coming in second at 220%.
They concluded that leucine is a “trigger” for muscle synthesis.
Researchers from McMaster University in Canada and Nestle Research Centre in Switzerland conducted the study. It was published in the February 2014 issue of The American Journal of Clinical Nutrition.
Leucine is an essential amino acid that stimulates skeletal muscle protein synthesis, which starts the muscle building process.
In addition to building muscle, leucine also helps regulate blood sugar levels. Foods rich in leucine include soybeans, lentils, beef, peanuts, salmon, eggs and milk.